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<h1>Practice</h1>

<p>This tab is used to add practice blocks in the experiment.</p>

<p>Once the blocking strategy chosen an experiment is organized as a hierarchy of blocks. Using this tab, practice blocks can thus be inserted before any block.</p>

<p>Practice blocks can be inserted at the beginning of the experiment (<b>Experiment level</b>) or before each experiments block of a given depth in the hierarchy of blocks (<b>Block<i>i</i> level</b>). Suppose the factors T and ID are both nested at <b><i>i</b></i> level. If T has two different values and ID three, there are six different types of blocks at level <b><i>i</b></i>. Inserting practice blocks at the <b>Block<i>i</i> level</b> means that theses practice blocks will be presented each time a block of a type that has never been presented yet begins. By default, if the blocks are repeated several times, practice blocks are presented only the first time a block occurs but by checking the box 'repetitions' they will be presented before all blocks, including those that are repetitions of blocks already presented.</p>

<p>Inserting a practice block at level <b><i>i</b></i> is achieved by letting the checkbox 'off' as unchecked. Then the practice block is defined by:
<br> - the number of trials it contains,</li>
<br> - the values of the different factors for the trials it contains. For each factor, you can choose to show (i) a sample of the values it can take, (ii) a fixed given value (e.g. T=Technique1) or (iii) a fixed value being the value of the factor in the next coming block.
<br> - the kind of block. A practice block can be made of trials similar to the experimental trials or it can be mode of trials of another kind. For example, experimental trials can be 2D pointing tasks while practice trials can be 1D pointing tasks to simply make the participant get used with the acceleration of the pointing device.
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<p>Of course, a practice session is not especially limited to a single block. The '+' button at the end of the line allows to add a block at the same level. Also, if there are block repetitions in the experiment, the practice session can appear before each repetition or not by checking or unchecking the 'repetitions' checkbox.</p>

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